Hum in my system; its the turntable R and L interconnects. Huh?
Pioneer PL-570 reconditioned turntable
EAR Phono Box
Cambridge Audio Integrated amp
DALI Floorstanders
I have a very pronounced "Hum" in my system, sounds like a 60cycle hum. I tried all the troubleshooting steps; it originates in the EAR, which has just recently been serviced and has new Goldline tubes. But here is the kicker, if I disconnect the R and L TT interconnects the hum cuts out and I get a fine white noise sound of much less volume. The TT produces the hum in the system even if the TT is unplugged from the wall receptacle. Removing the ground wire from the TT to the EAR has no effect. I can place my ear on the EAR case and hear nothing, dead quiet. A fault inside the TT?
All good suggestions! The cables from the TT are soldered in place, they can't be swapped. I would consider upgrading the cables if when I try my son's TT in the system, the hum goes away, I did try different cables between the EAR and the amp: no change. And tried a different input on the amp: no change. |
Update: I took the EAR over to my friends house and tried it in his system. The EAR was quiet. So it's for sure originating in the TT. Odd that the TT will generate this feedback even if its not plugged in. So its not being generated by energy in the TT, it must be related to a internal wiring fault or the picking up of interference. He has an oscilloscope and has offered to hook it up to the TT to look at the sine wave. I'm not an electrical engineer so not sure what I can learn from that. I also ran a ground wire from the EAR to the amp: no change. I have not tried the TT in another system, or a different TT in my system. More to follow. Thanks to all of you that have shared your expertise. It's a journey... |
Thank you. I did that and it did not correct the issue. My experienced audio friend took one listen to the system and said its interference being picked up by the TT R & L cables. BTW: the interference is there even if the TT is not plugged in. I have for sure narrowed it down to the TT as the source. |
@jereeb The problem is the ground wire on the phono isn't making a connection. So the thing to do is run a wire from the tonearm base (assuming its metal) to the chassis of the EAR. If there is a screw securing the arm to the plinth of the turntable that is the ideal point to put the wire. The RCA cables and cartridge connections are obviously OK. Its normal for the 'table to not be plugged into the wall and have this happen if the ground wire has an open connection. |
